The Coriolis flow meters is one of the most versatile, accurate, and adaptable types of flow meters. They measure mass flow, density, and temperature using the Coriolis effect. A fluid flowing through a pipe is deflected by the Coriolis inertial effect, which depends on its mass flow rate. The force exerted by the flow of a substance on a rotating tube provides a mass flow rate
A Coriolis flow meter's unique design allows it to measure viscous and non-conductive fluids, which other meters cannot measure. Using a Coriolis flow meter, you can measure mass flow, volume flow, density, and temperature. As the tubes oscillate, the Coriolis force is created based on the mass of the meter.
Over volumetric flow, which measures in gallons per minute, mass flow is preferred. A mass flow meter measures fluid flow in pounds or kilometers per second, which is considered to be a more accurate measurement, especially in custody transfers.
In the flow tube of the meter is a drive coil that vibrates the tube at its natural frequency. When there isn‘t any flow, the tube still vibrates, and the pickoffs produce a signal from the tube‘s vibrations. The movement is relative to one tube to the other.
When a fluid is introduced into the tube or tubes of the meter, they begin to twist or oscillate, rapidly. When the acceleration occurs, the tube or tubes experience a force proportionate to the material's mass. The force in the tube is reacted to by the material passing through, which is known as the Coriolis force. The diagram below illustrates the difference between no flow and flow.
The viscosity of a fluid is measured by torsional action at the center of the tube where a counter oscillating mass is located. In the motion of the tube, a shear force is applied to the fluid. It is possible for the meter to read the oscillating motion of the fluid and convert it into a numerical value based on its viscosity.
The viscosity lessens the torsional oscillation of the tube. In order to maintain the torsional oscillation, more power is required from the current with a high viscosity. Dynamic viscosity is measured by the amount of power required. In the diagram below, blue arrows indicate the motions of A and B of a dual tube Coriolis flow meter.
The time delay between the inlet and outlet sensors provides the data for mass flow. Additionally, this signal can be used to measure the density of a material. In particular, a Coriolis flow meter measures through vibrations at its frequency. Should the density change, then the frequency shifts accordingly; with a higher density lessening it and a lower density raising it. However, note that different measurements are necessary when gauging gas density opposed to solids or liquids.
Process Temperature Effect
It is controlled during the zeroing of the process conditions that the process temperature effect changes the accuracy of the sensor due to a change in the process temperature, which is different from the calibrated temperature.
When the temperature varies from the calibrated temperature, the process temperature can also affect the accuracy of the density measurement.